Method and apparatus for process control with in-die metrology

Abstract

Various embodiments include a method for providing instructions to a process tool. The method includes emitting an incident light beam at a substrate, receiving a reflected light beam from the substrate and determining a spectrum of the reflected light beam. The method further includes determining a first property of a first layer of the substrate and a second property of a second layer of the substrate, based on the spectrum determination. The method further includes comparing the first property of the first layer to a first reference property and comparing the second property of the second layer to a second reference property. The method further includes determining the instructions based on the first property comparison and the second property comparison; and providing the instructions to the process tool.

1. A method for instructing a process tool to make adjustments to a process comprising the steps of:
 emitting a first incident light beam at a first substrate; 
 receiving a first reflected light beam from the first substrate; 
 determining a first spectrum of the first reflected light beam; 
 determining a first property of a first layer of the first substrate based at least in part on the first spectrum; 
 determining a second property of a second layer of the first substrate based at least in part on the first spectrum; 
 determining a virtual cross-section of the substrate based on the first property and the second property; 
 comparing the first property to a first reference property; 
 comparing the second property to a second reference property; 
 wherein comparing the first property to the first reference property and comparing the second property to the second reference property comprises comparing the virtual cross-section of the substrate to a desired cross section; 
 determining desired adjustments to the process to make the properties of the first and second layers more closely conform to the first and second reference properties, based at least in part on the first property comparison and the second property comparison; and 
 providing instructions to the process tool to make the desired adjustments. 
 
     
     
       2. The method of  claim 1 , further comprising adjusting a process of the process tool based on the provided instructions. 
     
     
       3. The method of  claim 1 , further comprising adjusting a process of the process tool based on comparing the first property and the second property to a previous first property and a previous second property. 
     
     
       4. The method of  claim 1 , wherein determining the first property is also based on the first reference property. 
     
     
       5. The method of  claim 1 , wherein determining the second property is also based on the second reference property. 
     
     
       6. The method of  claim 1 , wherein determining the first property is also based on the first and second reference property. 
     
     
       7. The method of  claim 1 , wherein the step of determining what adjustments to the process are appropriate is further based on a comparison of the first property to the second property. 
     
     
       8. The method of  claim 1 , further comprising processing a second substrate. 
     
     
       9. The method of  claim 8 , further comprising:
 emitting a second incident light beam at the second substrate; 
 receiving a second reflected light beam from the second substrate; 
 determining a second spectrum of the second reflected light beam; 
 determining a property of a layer of the second substrate based on the second spectrum; 
 determining a relationship based on a comparison of the first property of the first substrate to the property of the second substrate; 
 modifying the instructions based on the relationship; and 
 providing the modified instructions to the process tool. 
 
     
     
       10. The method of  claim 9 , further comprising adjusting a process of the process tool based on the provided instructions. 
     
     
       11. The method of  claim 1 , further comprising:
 emitting an incident light beam at a reference substrate; 
 receiving a reflected light beam from the reference substrate; 
 determining a reference spectrum of the reflected light beam from the reference substrate; 
 determining a first reference property of a first layer of the reference substrate based on the reference spectrum; and 
 determining a second reference property of a second layer of the reference substrate based on the reference spectrum. 
 
     
     
       12. The method of  claim 1 , wherein the first property is the thickness of the first layer of the first substrate. 
     
     
       13. The method of  claim 1 , wherein the first property is the index of refraction of the first layer of the first substrate. 
     
     
       14. The method of  claim 1 , wherein the first property is the coefficient of extinction of the first layer of the first substrate. 
     
     
       15. The method of  claim 1 , wherein the diameter of the first incident light beam is larger than 19 millimeters. 
     
     
       16. A computer readable medium having embodied thereon a program, the program being executable by a computing device for performing a method for providing instructions a process tool to make adjustments to a process comprising the steps of:
 emitting a first incident light beam at a first substrate; 
 receiving a first reflected light beam from the first substrate; 
 determining a first spectrum of the first reflected light beam; 
 determining a first property of a first layer of the first substrate based on the first spectrum; 
 determining a second property of a second layer of the first substrate based on the first spectrum; 
 determining a virtual cross-section of the substrate based on the first property and the second property; 
 comparing the first property to a first reference property; 
 comparing the second property to a second reference property; 
 wherein comparing the first property to the first reference property and comparing the second property to the second reference property comprises comparing the virtual cross-section of the substrate to a desired cross section; 
 determining what adjustments to the process are appropriate to make the properties of the first and second layers more closely conform to the first and second reference properties based on the first property comparison and the second property comparison; and 
 providing instructions to the process tool to make the appropriate adjustments. 
 
     
     
       17. The method of  claim 16 , further comprising adjusting a process of the process tool based on the provided instructions. 
     
     
       18. The method of  claim 16 , further comprising processing a second substrate using the instructions. 
     
     
       19. The method of  claim 18 , further comprising:
 emitting a second incident light beam at the second substrate; 
 receiving a second reflected light beam from the second substrate; 
 determining a second spectrum of the second reflected light beam; 
 determining a property of a layer of the second substrate based on the second spectrum; 
 determining a relationship based on a comparison of the first property of the first substrate to the property of the second substrate; 
 modifying the instructions based on the relationship; and 
 providing the modified instructions to the process tool. 
 
     
     
       20. The method of  claim 16 , further comprising:
 emitting an incident light beam at a reference substrate; 
 receiving a reflected light beam from the reference substrate; 
 determining a reference spectrum of the reflected light beam from the reference substrate; 
 determining a first reference property of a layer of the reference substrate based on reference spectrum; and 
 determining a second reference property of a second layer of the reference substrate based on the reference spectrum. 
 
     
     
       21. The method of  claim 16 , wherein the first property is the thickness of the first layer of the first substrate. 
     
     
       22. The method of  claim 16 , wherein the first property is the index of refraction of the first layer of the first substrate. 
     
     
       23. The method of  claim 16 , wherein the first property is the coefficient of extinction of the first layer of the first substrate. 
     
     
       24. The method of  claim 18 , wherein the diameter of the first incident light beam is larger than 19 millimeters. 
     
     
       25. A metrology tool for instructing a process tool to make adjustments to a process comprising:
 an emitter configured to emit an incident light beam at a first substrate; 
 a receiver configured to receive a reflected light beam from the first substrate; 
 a spectrometer configured to determine the spectrum of the reflected light beam; and 
 a processor configured to:
 determine a first property of a first layer of the first substrate based on the spectrum; 
 determine a second property of a second layer of the first substrate based on the spectrum; 
 determining a virtual cross-section of the substrate based on the first property and the second property; 
 compare the first property to a first reference property; 
 compare the second property to a second reference property; and 
 wherein comparing the first property to the first reference property and comparing the second property to the second reference property comprises comparing the virtual cross-section of the substrate to a desired cross section; 
 determine what adjustments to the process are appropriate to make the properties of the first and second layers more closely conform to the first and second reference properties based on the first property comparison and the second property comparison; and 
 provide the instructions to the process tool to make the appropriate adjustments. 
 
 
     
     
       26. The metrology tool of  claim 25 , wherein the process tool is further configured to adjust a process of the process tool based on the provided instructions. 
     
     
       27. The metrology tool of  claim 25 , wherein the process tool is further configured to process a second substrate using the instructions. 
     
     
       28. The metrology tool of  claim 27 , wherein the processor is further configured to:
 receive a first property of a second substrate; and 
 modify the determined what adjustments to the process are appropriate based on a comparison of the first property of the first substrate to the first property of the second substrate. 
 
     
     
       29. The metrology tool of  claim 25 , wherein the first property is the thickness of the first layer of the first substrate. 
     
     
       30. The metrology tool of  claim 25 , wherein the first property is the index of refraction of the first layer of the first substrate. 
     
     
       31. The metrology tool of  claim 25 , wherein the first property the coefficient of transmission of the first layer of the first substrate. 
     
     
       32. The metrology tool of  claim 25 , wherein the diameter of the incident light beam is larger than 19 millimeters.